It bothers you because they're messing with a classic. It would be like someone touching up the smile on the Mona Lisa. Da Vinci didn't quite get it right. We'll fix it.
I understand that some changes are necessary to translate 1500 pages into 3 movies, but as long as they don't replace major characters I'm fine. Eliminating Bombadil makes sense, generally, though they will then need to explain where the hobbits' swords/knives come from since there can be no barrow wight now.